Re: [edk2 PATCH 00/48] ArmVirtPkg, OvmfPkg: virtio filesystem driver

["Ard Biesheuvel" <ard.biesheuvel@arm.com>]

On 12/20/20 1:09 AM, Laszlo Ersek wrote:
> On 12/18/20 18:44, Ard Biesheuvel wrote:
>> On 12/16/20 10:10 PM, Laszlo Ersek wrote:
>>> Ref:    https://bugzilla.tianocore.org/show_bug.cgi?id=3097
>>> Repo:   https://pagure.io/lersek/edk2.git
>>> Branch: virtio-fs (@ b8fd76d649d2)
>>>
>>> The first commit and the bugzilla ticket state the use case.
>>>
>>> References, including setup instructions:
>>> - https://libvirt.org/kbase/virtiofs.html
>>> - https://virtio-fs.gitlab.io/
>>>
>>> Useful UEFI shell commands for testing: output redirections, attrib,
>>> connect, cp, disconnect, edit, eficompress, efidecompress, hexedit, ls,
>>> map, mkdir, mv, rm, setsize, timezone, touch, type, vol.
>>>
>>> The series is largely structured as follows:
>>> - helper functions and FUSE command wrappers are implemented as required
>>>   by the next EFI_FILE_PROTOCOL interface,
>>> - said EFI_FILE_PROTOCOL interface is implemented,
>>> - lather, rinse, repeat.
>>>
>>> Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
>>> Cc: Jordan Justen <jordan.l.justen@intel.com>
>>> Cc: Leif Lindholm <leif@nuviainc.com>
>>> Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
>>>
>>> Thanks,
>>> Laszlo
>>>
>>> Laszlo Ersek (48):
>>>   OvmfPkg: introduce VirtioFsDxe
>>>   ArmVirtPkg: include VirtioFsDxe in the ArmVirtQemu* platforms
>>>   OvmfPkg/VirtioFsDxe: DriverBinding: open VirtioDevice, install
>>>     SimpleFs
>>>   OvmfPkg/VirtioFsDxe: implement virtio device (un)initialization
>>>   OvmfPkg/VirtioFsDxe: add a scatter-gather list data type
>>>   OvmfPkg/VirtioFsDxe: introduce the basic FUSE request/response headers
>>>   OvmfPkg/VirtioFsDxe: map "errno" values to EFI_STATUS
>>>   OvmfPkg/VirtioFsDxe: submit the FUSE_INIT request to the device
>>>   OvmfPkg/VirtioFsDxe: implement the wrapper function for FUSE_OPENDIR
>>>   OvmfPkg/VirtioFsDxe: add shared wrapper for FUSE_RELEASE /
>>>     FUSE_RELEASEDIR
>>>   OvmfPkg/VirtioFsDxe: implement
>>>     EFI_SIMPLE_FILE_SYSTEM_PROTOCOL.OpenVolume()
>>>   OvmfPkg/VirtioFsDxe: implement the wrapper function for FUSE_FORGET
>>>   OvmfPkg/VirtioFsDxe: add a shared wrapper for FUSE_FSYNC /
>>>     FUSE_FSYNCDIR
>>>   OvmfPkg/VirtioFsDxe: implement the wrapper function for FUSE_FLUSH
>>>   OvmfPkg/VirtioFsDxe: flush, sync, release and forget in Close() /
>>>     Delete()
>>>   OvmfPkg/VirtioFsDxe: add helper for appending and sanitizing paths
>>>   OvmfPkg/VirtioFsDxe: manage path lifecycle in OpenVolume, Close,
>>>     Delete
>>>   OvmfPkg/VirtioFsDxe: implement the wrapper function for FUSE_OPEN
>>>   OvmfPkg/VirtioFsDxe: implement the wrapper function for FUSE_MKDIR
>>>   OvmfPkg/VirtioFsDxe: implement the wrapper function for FUSE_CREATE
>>>   OvmfPkg/VirtioFsDxe: convert FUSE inode attributes to EFI_FILE_INFO
>>>   OvmfPkg/VirtioFsDxe: implement the wrapper function for FUSE_LOOKUP
>>>   OvmfPkg/VirtioFsDxe: split canon. path into last parent + last
>>>     component
>>>   OvmfPkg/VirtioFsDxe: add a shared wrapper for FUSE_UNLINK / FUSE_RMDIR
>>>   OvmfPkg/VirtioFsDxe: implement the wrapper function for FUSE_GETATTR
>>>   OvmfPkg/VirtioFsDxe: implement EFI_FILE_PROTOCOL.Open()
>>>   OvmfPkg/VirtioFsDxe: erase the dir. entry in
>>>     EFI_FILE_PROTOCOL.Delete()
>>>   OvmfPkg/VirtioFsDxe: implement the wrapper function for FUSE_STATFS
>>>   OvmfPkg/VirtioFsDxe: add helper for formatting UEFI basenames
>>>   OvmfPkg/VirtioFsDxe: implement EFI_FILE_PROTOCOL.GetInfo()
>>>   OvmfPkg/VirtioFsDxe: implement EFI_FILE_PROTOCOL.GetPosition,
>>>     .SetPosition
>>>   OvmfPkg/VirtioFsDxe: add a shared wrapper for FUSE_READ /
>>>     FUSE_READDIRPLUS
>>>   OvmfPkg/VirtioFsDxe: implement EFI_FILE_PROTOCOL.Read() for regular
>>>     files
>>>   OvmfPkg/VirtioFsDxe: convert FUSE dirent filename to EFI_FILE_INFO
>>>   OvmfPkg/VirtioFsDxe: add EFI_FILE_INFO cache fields to VIRTIO_FS_FILE
>>>   OvmfPkg/VirtioFsDxe: implement EFI_FILE_PROTOCOL.Read() for
>>>     directories
>>>   OvmfPkg/VirtioFsDxe: implement EFI_FILE_PROTOCOL.Flush()
>>>   OvmfPkg/VirtioFsDxe: implement the wrapper function for FUSE_WRITE
>>>   OvmfPkg/VirtioFsDxe: implement EFI_FILE_PROTOCOL.Write()
>>>   OvmfPkg/VirtioFsDxe: handle the volume label in
>>>     EFI_FILE_PROTOCOL.SetInfo
>>>   OvmfPkg/VirtioFsDxe: implement the wrapper function for FUSE_RENAME2
>>>   OvmfPkg/VirtioFsDxe: add helper for composing rename/move destination
>>>     path
>>>   OvmfPkg/VirtioFsDxe: handle file rename/move in
>>>     EFI_FILE_PROTOCOL.SetInfo
>>>   OvmfPkg/VirtioFsDxe: implement the wrapper function for FUSE_SETATTR
>>>   OvmfPkg/VirtioFsDxe: add helper for determining file size update
>>>   OvmfPkg/VirtioFsDxe: add helper for determining access time updates
>>>   OvmfPkg/VirtioFsDxe: add helper for determining file mode bits update
>>>   OvmfPkg/VirtioFsDxe: handle attribute updates in
>>>     EFI_FILE_PROTOCOL.SetInfo
>>>
>>
>> This looks carefully crafted, and modulo my two questions, I won't be
>> able to spend more time on this than I have going through these
>> patches today.
>>
>> So please feel free to merge this whenever you feel it's ready.
>>
>> For the series,
>>
>> Acked-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
> 
> Thank you.
> 
> Before I posted the series, I tested it very thoroughly, including build
> tests (at every patch, and a Local CI run as well). I created a test
> plan and went through it meticulously (it took hours).
> 
> The only thing I couldn't test that way was (obviously) building on
> Windows. So clearly now that I've tried merging the series at
> <https://github.com/tianocore/edk2/pull/1248>, that's what fails.
> Because, this is the first time that EmbeddedPkg/TimeBaseLib is seen by
> the Visual Studio compiler, and Visual Studio complains:
> 
>> ERROR - Compiler #2220 from
>> d:\a\1\s\EmbeddedPkg\Library\TimeBaseLib\TimeBaseLib.c(111):   the
>> following warning is treated as an error
>> WARNING - Compiler #4244 from
>> d:\a\1\s\EmbeddedPkg\Library\TimeBaseLib\TimeBaseLib.c(111):   '=':
>> conversion from 'UINTN' to 'UINT32', possible loss of data
> 
> It happens to be correct:
> 
>     99  /**
>    100    Converts EFI_TIME to Epoch seconds (elapsed since 1970 JANUARY 01, 00:00:00 UTC)
>    101   **/
>    102  UINT32
>    103  EFIAPI
>    104  EfiTimeToEpoch (
>    105    IN  EFI_TIME  *Time
>    106    )
>    107  {
>    108    UINT32 EpochDays;   // Number of days elapsed since EPOCH_JULIAN_DAY
>    109    UINT32 EpochSeconds;
>    110
>    111    EpochDays = EfiGetEpochDays (Time);
>    112
>    113    EpochSeconds = (EpochDays * SEC_PER_DAY) + ((UINTN)Time->Hour * SEC_PER_HOUR) + (Time->Minute * SEC_PER_MIN) + Time->Second;
>    114
>    115    return EpochSeconds;
>    116  }
> 
> This was discussed on the list earlier, when the function was duplicated
> for the HTTP dynamic command:
> 
> - https://edk2.groups.io/g/devel/message/64933
> - https://edk2.groups.io/g/devel/message/65186
> 
> Compare EfiTimeToEpoch() in
> "ShellPkg/DynamicCommand/HttpDynamicCommand/Http.c".
> 
>    430  STATIC
>    431  UINTN
>    432  EFIAPI
>    433  EfiTimeToEpoch (
>    434    IN  EFI_TIME  *Time
>    435    )
>    436  {
>    437    //
>    438    // Number of days elapsed since EPOCH_JULIAN_DAY.
>    439    //
>    440    UINTN EpochDays;
>    441    UINTN EpochSeconds;
>    442
>    443    EpochDays = EfiGetEpochDays (Time);
>    444
>    445    EpochSeconds = (EpochDays * SEC_PER_DAY) +
>    446                   ((UINTN)Time->Hour * SEC_PER_HOUR) +
>    447                   (Time->Minute * SEC_PER_MIN) + Time->Second;
>    448
>    449    return EpochSeconds;
>    450  }
> 
> So, in order to merge this series, I'll first have to fix
> EfiTimeToEpoch() in EmbeddedPkg :(
> 
> I wish the fixed version in
> "ShellPkg/DynamicCommand/HttpDynamicCommand/Http.c" had been contributed
> back to EmbeddedPkg.
> 
> Anyway, that is for 2021.
> 
> Thank you for checking the series so quickly; I know it's a lot!
> Laszlo
> 

Thanks for clearing up the outstanding questions.

For the EmbeddedPkg change from UINT32 to UINTN

Acked-by: Ard Biesheuvel <ard.biesheuvel@arm.com>

although I suppose you will have to preserve the prototype, so adding a
(UINT32) cast to line 111 is probably the best approach here.

-- 
Ard.